Introduction to Retrosynthesis

Question 1

What is often a good bond to break in a ketone

Answer 1

1. C-C bond between the carbons that are alpha and beta to the ketone

Question 2

How do you show which bond is being disconnected

Answer 2

1. Wiggly line

Question 3

What do you get when you break a bond

Answer 3

1. Two different pairs of synthons

2. The electrons could go to one of the fragments or the other

Question 4

What are synthons

Answer 4

1. They are not real compounds

2. They are hypothetical compounds that would react together to form the desired bond- if they existed

Question 5

What do you do once you have pairs of synthons

Answer 5

1. Determine the real life equivalents

Question 6

What is the real life equivalent for a primary alkyl cation

Answer 6

1. Corresponding alkyl halide

2. React by SN2 mechanism

Question 7

What is the rle for a carbanion at the alpha position of a carbonyl

Answer 7

1. Corresponding enolate

2. Formed by deprotonation of that carbonyl

Question 8

Once you have RLEs what do you do

Answer 8

1. Write the forward reaction